Slow-release magnet.



PATENTED JULY 24, 1906.

L. H. TEUL EN. SLOW RELEASE MAGNET;

APPLICATION FILED DEC. 22. 1903.

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W/TNES E PATENTED JULY 24, 1906. L. H. THULLEN. SLOW RELEASE MAGNET.

APPLICATION FILED D130. 22. 1903-.

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APPLICATION FILED DBO. 22. 1903.

am T B E H A S T E B H s 4 PATENTED JULY 24, 1906.

APPLICATION FILED DEC. 22. 1963.

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LOUIS H. THULLEN. OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR' TO THE UNION SWITCH & SIGNAL (10.. OF SVVISSVALE, CORPORATION OF PENNSYLVANIA.

PENNSYLVANIA, A

SLOW-RELEASE MAGNET.

To all whrmt it may concern- Be it knownthat I, LOUIS H. THULLEN, a citizen of the United States, residing at Edge- Wood, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Slow-Release Magnets, of which the following is a specificatlon.

My invention relates to slow-release magnets, and it is particularly adapted for railway' signaling purposes. For example, it may be used to great advantage in the slot mechanism shown in United States Patent No. 611,943, granted October 4, 1898, upon invention of J. G. Schreuder or in any other signal mechanism or signal systemwhere it is desired to have a slow release of an arma: 1 ture from itsmagnet or to prevent the release of an armature from its magnet for a period of time. i

Iwill describe a slow-release magnet and several modifications thereof and its application to a railway-signal of the type illustrated in said patent, each embodyin my invention, and then point out the novel features thereof in claims.

In the accompanying drawings, Figure 1 is a diagrammatic and perspective view of a magnet embodying my invention. Figs. 2 to 10, inclusive, each diagrammatic and perspective view showing modifications, each of which embodies my invention. Fig. 11 is a view, partly in elevation and partly in vertical section, of a railway-signal of the type referred to in Patent Nol 611,943 having my invention applied thereto. Fig. 12 is a detail view of the slot mechanism of the mechanism of said patent having my invention applied thereto. Fig. 13 is an enlarged detail view.

Similar letters of reference designate corresponding parts in all of the figures.

Referring now to the drawings, and particularly to Fig. 5, which shows a simple form of magnet embodying my invention, A desig-. nates a soft-iron magnet-core; B, an energizing magnetizing-winding for the core; D,

a source of current-supply for the winding, and F a winding of low resistance. This latter is preferably in the form of a copper tube or cylinder. Instead a plurality of short copper tubes or cylinders may be employed Specification of Letters Patent.

Application filed December 22, 1903- Serial No. 186.183-

?atented July 24, 1906.

or a plurality of copper washers. This form of the invention ispreferably used in a slot mechanism of a railway-signal, (see Figs. 11 and 12,) with the exception that the copper tube F is placed next the iron core instead of the energizin -winding B, as illustrated in Fig. 5. Also in the form of the invention in Figs. 11 and 12 insulation I in the form of paper or other similar material is placed between the energizin -winding B and the tube F. This is more c early illustrated in Fi 13. This use of the paper I or other suitab e insulation I do not claim to be new.

. Any dimensions of tubes or washers may be employed.

Referring now to Fig. 1, A designates the soft-iron core; B, the energizing or magnetizing'coil; E, a high-resistance coil or winding which is closed upon itself, and F a copper tube. As shown in this figure, the copper tube is placed next the core instead of outside the winding B, as in Fig. 5, the magnetizingwinding B next to the copper tube, and the high-resistance winding next to the magnetizing-Winding.

D designates the source of current-supply for the magnetizing-winding.

So long as the circuit of the magnetizingwinding is uninterrupted the core A will be magnetized and will attract and hold to it a suitable armature. As soon as the circuit of the magnetizing-winding is opened or interrupted a change of flux occurs in the magnetic circuit. This change in flux in turn causes a current to flow in both the copper tube and all short-circuited circuits, which current is in a direction similar to the magnetizing current. This current flowing in this direction sets up a counter magnetizing flux to that due to breaking the circuit of the magnetizing-Winding and has a tendency. to retard the change of flux, due to the opening or interruption of the magnetizing-circuit for a. period of time. The copper tube being a circuit of low resistance, the current induced in it is at its maximum at a period of time closely following the opening or interruption of the magnetizingcircuit, and the retardation due to this low-resistance circuit is at a period closely following the opening or inter provided the core would drop its armature immediately upon the opening or interruption of the energizing-circuit.

In the construction shown in Fi 1 the winding E, which is closed upon itse f, has a high resistance, and therefore more self-induction than the copper tube, which causes the period of maximum current induced in this Winding to be at a time later than that of the copper tube. This current being at a later period, further retards the demagnetization of the iron core, and hence adds to the value of the copper tube.

. The construction shown in Fig. 2 is the same as that shown in Fig. 1, with the exception that the co per tube is provided with a head or washer at each of its ends, the purpose of which is to reduce as much as possible the resistance of the copper tube.

The construction shown in Fig. 3 is like that shown in Fig. 2, with the addition that a relay or magnet H controls the magnetizing circuit or winding B. The armature K of the magnet H is movable between two contacts M and L. When the magnet H is energized, it holds its armature against the contact .M, and when the armature K is against the contact Mthe source of current-supply D is ineluded in the magnetizing-circuit. When the magnet H is deprived of exciting-current or is denergized, the armature K engages contact L and closes the magnetizin -winding on itself. With this construction t e advantages set forth in regard to the construction shown in Fig. 1 are obtained, and the following additional advantage is also obtained: The current generated in the ma netizing-coil due to the change of flux in t e magnetic circuit upon the opening or interruption of the-ma netizing-circuit is not in phase or in step wit the current generated in the copper tube,

that is, the induced current reaches its maximum value at a period of time later than the current induced in the copper tube, and this current bein out of phase .or step in the co per tube, an at a later period it prolongs tl ie magnetization of the core A to a period of time later, due to the current in the cop or tube. The magnetizing winding of coi is composed of a greatnumber of turns, which grlves it considerable self-induction, and this causes the current induced in it to be out of step with the current in the copper tube, the

co per tube having very little self-induction. n the construction shown in Fig. 4 the Winding of low resistancethat is, the copper tubeis shown as being next to the iron core and a srbeing provided with copper heads or washers F, the purpose of which has been hereinbefore explained. In addition a relay H or other source of controlling power is provided to control the source of current-supply D and to close the energizing-winding on itself when the relay H is denergized.

In the construction shown in Fig. 6 the mag- I netizing-winding B is placed next'to the core,

and next to this is laced th'e high-resistance winding, which is c osed on itself, and outside of all is the copper tube F. In addition the relay H and its armature K, working between the contacts M and L, is em 10 ed.

The construction shown in ig. 7 is the same as that shown in Fig. 6, with the exception that the copper tube is located between the two windings. F i 8 is the same as Fig. 7, with the exception t at the copper tube is provided with copper heads F.

In Fig. 9 I employ a number of copper washers F on the tube F. The magnetizingwinding B is wound either between all the Washers or between two or more. The highresistance winding E is wound either between all the washers F or between two. Fig. 10 is the same as Fig. 9, except that the copper tube is omitted and no relay is em loyed.

Figs. 1 1 and 12 illustrate the app ication of my invention to a slot mechanism of a railway-signal, and the great advantage referred to in the preamble of the specification will now be explained. The construetionof the slot-arm is clearly set forth in the Patent No. 611,943, hereinbefore referred to, as is the operating mechanism. I will therefore only herein briefly describe the parts of such slot-arm and the railway-signal.

Referring now to Fig. '11, P designates an electric motor, which through a trainof gears drives an endless chain or chains Q always in the same direction. The number of chains driven by the motor depends upon the number of slot-arms employed. In the present instance there are two chains and two slotarms R R. Each slot-arm, as shown, com- ICO prises a frame 1", a chain of levers, a finger r,

which coacts with an endless chain Q, a magnet or magnets 1' embodying my invention, and anarmature 1", which when attracted by the magnet 1 holds the finger 1" rigid, so that the frame 1" ma bemoved by the endless being operatively eonnecte with a signal device S S. When the frame is moved upward by the endless chain, the signal device is moved from a horizontal position indicating danger to an inclined position indicating caution or safety, and when the fin er r is disengaged from the catch r or endless chain the weight of the signal device and rod 1 causes the frame to drop and the signal device to move to its horizontal or danger position of indication. In Fig. 11 I have shown one frame elevated and the signal device with which it is connected in its inclined position and the other frame in its lowermost position ready .to be elevated and 130' the signal device connected therewith in its tions from a horizontal position.

In order now that the great advantage heretofore referred to may be understood, it will be necessary to describe a system of signaling in which a railway-signal comprising a slot mechanism is employed. In the Schreue der patent, No. 611,943, referred to, a home and .distant signaling system is illustrated and described. In this type of system a home signal S and a distant signal S are 10- cated at the same point, and generally for the sake of economy, as in this patent, both the home and distant signals are operated by the same motor. In such a system it often happens that the home si nal will be in one position of indication, w ile the distant signal will be in a different position of indication. For example, consider two block-sections and a home and distant signal located atthe entrance end of each block-section. When a train enters the first block-section, both the home and distant signals of that block-section will move to their danger position, this being accomplished by breaking the circuit on the magnets r of the slot-arms. When the train moves out of the first block-section into the second block-section, both the home and distant signals of the second block-section move to their danger positions, while the home signal of the first block-section is moved to its safety position, leaving the distant signal at the first block-section in its danger position, this signal beingheld in its danger position until the home signal of the second blockmoves to safety, at which time the distant signal moves to safety. In other words, the osition of a distant signal is controlled by t e position of its home signal, except of coursewhen a home signal immediately above a distant signal is in a danger position. The above operations -take place as a train moves'through successive block-sections. The movement of the home and distant signals are controlled from trackcircuits, which, as well known in the art, comprise a source of current at one end of the block-section and a relay at the other end,

whose armature or armatures close local circuits on the magnets of the slot mechanisms and motor of the operating mechanism of the railway-signals.

In the system to which my invention is articularly applicable the relay is of a poarized typethat is,.the relay comprises a and polar armature controls the circuit of the distant si al. The polar armature is moved to close t e circuit 0 the distant signal only when the current from the battery ows in a determined direction, and this determined direction is obtained through what is known as a ole-changer, which'is operated from every ome signal. trated in Fig. 11 and desi'nated U. The pole-changer, as is well un erstood, is connected with the track-battery and track-rails of a block-section. Thus it will be seen that when a home signal-is moved, say, from its safety position to its danger position it operates its pole-changer to such a position as to have the polar armature move to open the circuit on the distant signal, and when the home si nal is moved from its danger position to its safety position the pole-changeris again operated; but this operation causes the cur-- rent to flow in such direction to move the polar armature to-close' the local circuit. This system is well known in the art. 4

In operating a pole-changer it is apparent that at some instant the battery of a blocksection is cut off from the track-rails, thereby denergizin the relay of that bloclosection. Therefore the home signal of that blocksection should be in its safety position it would move to its danger position, thus giving a false indication. By ny invention this is prevented, for when the current is cut off from the slot-magnet comprised in the slot mechanism for the home signal the copper tube has induced in it a current which tends to'build up the rapidly-dying magnetism of the iron core, and thus prevent the release of the armature. The momentary break by the pole-changer in the connection of the track-battery with the track-rails is only for an instant, so that the retardation of approximately a second is suflicient to prevent the releasev of the armature. Without this retardation the home signal would move to its danger position or nearly to its danger position, thus requiring an operation of the motor and a consequent loss of energy.

What I- claim as my invention is I. The combination in a slot-arm for railway-signals with a suitable frame, an engaging finger and levers carried thereby, and a magnet and armature which armature when attracted by the magnet holds the finger and levers rigid, said magnet being provided with a closed circuit which upon interruption of the current normally flowing through the winding of the magnet retards the release of the armature.

2. In a railway-signal, the combination with a signal device, means comprising a motor for moving it from one position to another position, a slot mechanism for holding it in the position to which it has been moved, said slotmechanism comprising a magnet and ar- A pole-changer is illuscuit of low resistance which upon interruption of the current normally energizing the magnet retards the demagnetization of thecore of the magnet and therefore'retards the release of the armature.

Y 3. The combination in an electromagnet clutch or slot mechanism for railway-signals, of' means for maintaining a closed circuit 'around the magnet-cores of the device after interruption of the circuit normally ener izing the magnet, said circuit derivin its e ectrical energy through the self-inductlon of the magnet and thereby maintaining for a short period the magnetic energ of the cores after interruption of its normaly energizing cur- :5 rent.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

.. v LOUIS H. THULLEN Q T Witnesses:

W. 'L. MGDANIEL,

GEO. McCORMIcK. 

